.Dd Created:2025-10-03|Updated:2025-10-19|
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.de oit
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.de obdi
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.de obdl
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.de obc
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.de obc2
.obc opt desc
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.obc option arguments description
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.Dt SSH oh
.Os OpenBSD 7.7 linux|
.Nm ssh
.Nd usage, configuration and tips
.Sh SYNOPSIS
.Dl ssh [OPTION] REMOTE_HOST [COMMAND]
.Sh TOC
.Bl -column -offset indent "Sy It - Sx connect through vpn on ssh tunnel "
.It Sx COMMAND LINE
.It - Sx options
.It - Sx x forwarding
.It Sx TUNNEL
.It - Sx create
.It - Sx connect through vpn on ssh tunnel
.It - Sx commands
.It Sx CONFIGURATION
.It - Sx example
.It - Sx control master
.It Sx SSH KEYS
.It Sx TODO
.It Sx SEE ALSO
.El
.Sh COMMAND LINE
.Ss options
.Bl -column ".Sy x forwarding "
.It -f Ta : fork
.It -L Ta : local forward
.It -D Ta : dynamic forward
.El
.Ss x forwarding
.obdi does not work on slackware
.Dl ssh -X
.oit trusted, works on debian/slackware
.Dl ssh -Y
.El
.Sh TUNNEL
.Ss create
Example: This can be used to create a socks proxy for a browser.
.Dl ssh -f -D $PORT $SERVER sleep 30000
.obdi D bindaddres:port / port (assumes localhost)
.oit sleep 30000 : keep the connection alive with sleep command
.El
.Ss connect through vpn on ssh tunnel
Example: If a SQL Server is only accesible in a different network, a tunnel can be created to access the SQL server through a computer that is accessible from outside that network.
.Ss commands
.Dl ssh -f -L 127.0.0.1:$PORT:$TARGET_SERVER:$TARGET_PORT $SSH_SERVER_USR@$SSH_SERVER sleep 30000
.Dl ssh -f -L 127.0.0.1:1234:SQL_server:1433 user@ssh_server sleep 30000
.onote NOTE: on Microsoft SQL Server Studio use 127.0.0.1,1234
.Sh CONFIGURATION
To add configuration options for specific host:
.obdl $HOME/.ssh/config
Host hostname
	 [SSH OPTION]
.Ed
.Ss example
This will always use port 8686 to connect to hostname:
.obdl Host hostname
	Port 8686
.Ed
.Ss control master
.onote NOTE: The user needs to have write permissions in the directory where the socket will be created.
Create a persistent connection when connecting to a remote machine. Eg.:
.Dl ssh -f remote sleep 30
.obdl Host [HOST]
	ControlMaster auto
	ControlPersist yes
	ControlPath [PATH_TO_CONTROL_SOCKET]/%r@%h:%p
.Ed
.Ss Commands
The socket can be controlled using -O:
.Li ssh -O [stop|exit|cancel|check|forward|proxy] HOST
.obc2
.It stop Ta | stop accepting requests.
.It exit Ta | exit master.
.It cancel Ta | cancel forwardings.
.It forward Ta | request forwardings.
.It proxy Ta | connect to master in proxy mode.
.El
.Sh SSH KEYS
.Dl ssh-keygen
Copy the resulting pub contents to the corresponding Host.
.Sh TODO
.obdi Review -L.
.oit Add better examples.
.El
.Sh SEE ALSO
.opsy OpenBSD manpages:
.oxr ssh 1
.oxr ssh_config 8
.Xr sshd_config 8
.El
.Sh AUTHORS
.An -nosplit
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